\ntemplate <class Element> class DefaultElementTraits {\npublic:\n    typedef  DoubleListAnchor Element::*ListAnchorField;\n    static ListAnchorField listAnchor(){return &(Element::listAnchor);}\n    };\n\ntemplate <class Element, class ElementTraits = DefaultElementTraits<Element> >\nclass AnchoredList\n{\n};\n